Unbalance of uplink coverage and downlink coverage, as a common problem in a mobile communication network, is usually incurred by the limited uplink coverage. In case of limited uplink coverage, user equipment (UE) can not communicate with the network even with a highest transmitting power, for the reason of a large uplink pathloss or a large uplink interference. Execution of UE services may be influenced by a poor uplink coverage, for example, UE call establishment may fail for increasing times, UE calls may drop for increasing times, and the quality of uplink voice is decreased.
Conventionally, a measurement item related to the uplink coverage is mainly collected by the communication network with a minimized drive test (MDT) function defined in the 3rd Generation Partnership Project (3GPP) protocol. A measurement item M2, i.e., a power headroom (PH), is configured in an MDT task. PH may function as the measurement item related to the uplink coverage of the UE, and the intensity of the uplink coverage of the UE is determined based on the PH value.
Conventionally, UE sends the PH value to an evolved Node B (eNB) through Media Access Control (MAC) protocol. An element manager (EB), or a mobility management entity (MME) in a core network node has created an immediate minimized drive test (Immediate MDT) task to instruct the eNB to collect the PH value. The eNB saves the received PH value in an MDT measurement report and sends the MDT measurement report to a trace collection entity (TCE), so that the TCE may determine the intensity of the uplink coverage of the UE based on the PH value in the MDT measurement report.
However, the problem in uplink coverage can not be truly reflected by the PH reported by the UE, and the uplink pathloss and uplink interference of the UE may be wrongly determined with a coverage optimization application in the TCE layer.